30
VLT
®
Series 3500
Motor Connections
All types of three-phase asynchronous standard motors
can be used with the VLT Series 3500.
Wire the motor for the proper voltage as shown on the
motor nameplate. Wire the motor to terminals U, V, and
W (96, 97 and 98) on the drive.
Direction of Rotation
The factory setting gives clockwise rotation when the
output of the VLT Series 3500 has been connected as
follows:
Terminal 96: connected to U
Terminal 97: connected to V
Terminal 98: connected to W
The direction of rotation can be changed by swapping
any two motor wires.
Parallel Connection of Motors
VLT Series 3500 can control several motors connected in
parallel. If the motor speeds are to be different, motors of
different rated speeds must be used. The speed of all of
the motors will change simultaneously. The ratio between
the rated motor speeds will be maintained over the whole
range.
The total current consumption by the motors must not
exceed the maximum rated output current of the drive.
If the motor sizes vary considerably, the speeds may be
different when run slowly. This is because small motors
have a relatively high resistance in the stator and
therefore require a higher voltage at start and at low
speeds than larger motors. This should not be a concern
in HVAC applications.
In systems with parallel motor operation, the electronic
thermal relay cannot be used as motor protection of an
individual motor. This is because the output current must
be programmed to match the overall motor current.
Consequently, additional motor protection is required,
such as individual thermal relays or thermistors in every
motor.